In a mobile electronic device such as a cellular phone, or the like, normally a secondary battery that can be charged/discharged repeatedly with electricity is employed to secure a power source. Also, some of conventional electronic devices are designed to charge a secondary battery in a noncontact manner (see Patent Literature 1, for example).
In the electronic device that puts the secondary battery on charge in a noncontact manner, when a power receiving coil for noncontact charging and a loop antenna for proximity noncontact communication (Felica (registered trademark), or the like) are arranged in close vicinity to each other, it is probable that a malfunction is induced in the proximity noncontact communication due to an adverse influence of a harmonic noise generated in the power receiving coil.
Also, as the method of preventing the adverse influence of such harmonic noise, in Patent Literature 2, for example, the technology to shift a resonance frequency of one tuning circuit in two proximity noncontact communication antennas or more from resonance frequencies of the remaining tuning circuits respectively is disclosed.    Patent Literature 1: JP-A-2000-076399 (Japanese Patent No. 318086)    Patent Literature 2: JP-A-2006-295469